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Biomedical subjects

Y Shu

Publications and source records attributed to Y Shu.

At least 55 records · Page 3Linked to original sources
PubMed1999

[Changes of lipids metabolism during gallstone formation in rabbit model and the effects on these changes by high density lipoprotein preparation injection].

To study the changes of lipids metabolism during gallstone formation and the effects fo the exogenous high-density lipoprotein (HDL) preparation on the formation of gallbladder stone in rabbit model in which the stones were induced by high-cholesterol (HC) diet. The plasma lipids, the bile cholesterol, the activity of plasma lecithine cholesterol acyltransferase (LCAT), the bile acids in both bile and plasma, and the incidence of stone formation were investigated in the control group, HC group, and HC + HDL group (in this group the rabbits were given HDL preparation intravenously regularly). The results showed that the lipids metabolic disorder was characterized by a large amount of cholesterol accumulated in the rabbit's body and when the liver cleaned the accumulated cholesterol, the ratio of biliary cholesterol to bile acids was significantly increased. The latter could cause the production of lithogenic bile. Thought HDL preparation could decrease hepatic cholesterol and increase the level of plasma HDL2-C and the activity of LCAT, it could not lower the incidence of gallstone formation. The results suggest that the HDL preparation had some effects on lipids metabolism, but no significant effect on gallstone formation in rabbit model has been evidenced, so the problem awaits further studies.

Animals↗
PubMed1999

[Change of high density lipoprotein receptor of hepatocyte during cholesterol gallstone formation in rabbit model].

In order to study the formation of cholesterol gallstone through rabbit model which was induced by high cholesterol diet (HCD), we investigated the high density lipoprotein receptor (HDLr) activities of hepatocytes, total bile acids and cholesterol of common duct bile at 1 week(1 w), 2 weeks(2 w), 3 weeks (3 w) and 4 weeks(4 w) in comparison with those of a control group respectively. The results were as follows: 1. The HDLr Bmax decreased and the kd value increased significantly (1 w group vs control group, P < 0.05); In 2 w group the two variables recovered to the level of control group; and after that, the HDLr Bmax increased and Kd value decreased markedly (3 w and 4 w groups vs control group, P < 0.05). 2. Total bile acids in bile increased slightly in 1 w group (vs control group, P > 0.05), then decreased in 2 w, 3 w and 4 w groups (4 w group vs control group, P < 0.05). 3. The concentration of cholesterol in bile increased gradually as the time of feeding HCD went on (3 w and 4 w groups vs control group, P < 0.05). The results demonstrated that owing to the intake of HCD with the passage of time, the activity of HDLr was up at the beginning and down gradually in the rest period. The change in concentrations of bile acids was similar to that of HDLr, and the concentration of cholesterol in bile was foreign to the change of HDLr. These results suggest that the decrease of HDLr activity may cause the absence of material for bile acids synthesis and it may play an important role in the formation of gallstone.

Animals↗
PubMed1998

Activation of bovine tracheal chloride channels by amino group-specific reagents.

1. The predominant Cl- channel in bovine tracheal epithelial cells has a conductance of approximately 71 pS and accounts for more than 80 % of the total chloride conductance. We examined the effects of protein-modifying reagents on channel function and found that amino groups are critically involved in gating. 2. Patch clamp studies showed that lysine-specific reagents, such as dimethyl adipimidate (DMA), significantly increased the channel open probability, but not its conductance. This suggests that modified residues are involved in the gating mechanism, but are distant from the channel permeation pathway. 3. Kinetic analysis of channel activity showed that histograms of open and closed durations could be well fitted by double exponential distributions, suggesting that the channel has at least two open and two closed states. DMA did not change the number of open or closed states, but increased channel mean open time. 4. Since membrane impermeant reagents were effective only from the extracellular side, we conclude that lysine residues in the extracellular domain of the channel are critically involved in gating. These residues may present an important target for site-directed mutagenesis and pharmacological activation of Cl- channels in epithelial cells.

Animals↗
PubMed1998

Determination of amitriptyline and nortriptyline in human liver microsomes with reversed-phase HPLC in vitro.

AIM: To develop a method for simultaneous determinations of amitriptyline (Ami) and its metabolite nortriptyline (Nor) in human liver microsomes. METHODS: An incubation buffer containing microsomes, NADPH-generating system, and Ami, after termination of enzyme reaction and desipramine (Des) as internal standard (IS), was extracted with diethy ether and separated on a reversed-phase ODS column. Detection was achieved at 242 nm by ultraviolet detector. RESULTS: No potential interfering peaks were found. Ami and Nor gave rapid elution and baseline resolution. The linear curves of both analyses ranged 0.02-10 nmol and the limit of detection was 0.01 nmol. The recovery (94%-101%) had good precision with relative s of < 8.3%. CONCLUSION: This method is rapid, sensitive, and simple for studying the metabolism of Ami and Nor.

Amitriptyline↗
PubMed1998

[Study on the improvement of bone marrow microenvironment by ligustrazine in immune-induced aplastic anemia mice].

OBJECTIVE: To explore the effects of ligustrazine on bone marrow microenvironment and its mechanism in aplastic anemia (AA). METHODS: Each immune-induced AA mouse was gastric fed by 4 mg ligustrazine twice a day. On the 10th day, the ulnar bone marrow partial pressure of oxygen (PbO2) was determined in vivo by a PO2 sensory needle. Then the histological features, fibroblastic colony forming unit (CFU-F) yields and the adhesive function of stromal cells of the bone marrow were assayed in vitro. RESULTS: The PbO2 in ligustrazine-treated group was 10.32 +/- 1.27 kPa, while in AA group was 4.32 +/- 2.86 kPa (P < 0.001). In AA group, the microvessels were expanded, broken and being stasis. The percentage of hematopoietic tissue volume was 24.9% +/- 9.6% and the CFU-F yields was 12.5 +/- 7.3/2 x 10(6) BMNC. The microvessels in ligustrazine group were more clear and intact, not being broken and had no stasis. The percentage of hematopoietic tissue volume was 52.8% +/- 15.6% and the CFU-F yields was 31.5 +/- 10.6/2 x 10(6) BMNC. In ligustrazine group, the adhesive function of stromal cell layer cultured with bone marrow nucleated cells from normal mice was 72.7% +/- 7.8%, which was not different from that in normal group (73.4% +/- 3.4%), but much higher than that in AA group (56.2% +/- 9.8%, P < 0.01). CONCLUSION: Ligustrazine can promote the rehabilitation of bone marrow microvessels in AA mice, increasing the oxygen supply for bone marrow microenvironment, promoting the growth of stromal cells and strengthening their adhesive function. Ligustrazine enbances the bone marrow hematopoietic cells proliferation by improving their microenvironment.

Anemia, Aplastic↗
PubMed1998

[Effect of ligustrazine on CD34 antigen expression of bone marrow cells in immune-mediated aplastic anemia mice].

OBJECTIVE: To explore the effect of ligustrazine on CD34 antigen expression of bone marrow cells in immune-mediated aplastic anemia (AA) mice. METHODS: The model of immune aplastic anemia mice was induced by means of 6.0 Gy60Co gamma-ray irradiation and lymphocyte infusion through tail vein. The mice were divided into 3 groups: the normal group, the AA control group and the ligustrazine group. Mice of the ligustrazine group were fed by 4 mg of ligustrazine injection twice a day by gastrogavage. On the 10th day, CD34 antigen expression intensity of bone marrow cell membrane was measured by flow cytometer analysis system. RESULTS: CD34 antigen expression intensity of ligustrazine group was 77.6 +/- 6.5, with no statistic difference from that in the normal group (80.0 +/- 2.6), while that of the control group was much higher (68.6 +/- 4.5, P < 0.05). CONCLUSIONS: Ligustrazine could promote proliferation of stem and progenitor cell of AA mice through influencing on bone marrow micro-environment so as to increase the CD34 antigen expression of bone marrow cells.

Anemia, Aplastic↗
PubMed1998

[Effects of composite blood-activating decoction on bone marrow microenvironment in mice of immune-induced aplastic anemia].

OBJECTIVE: To explore the mechanism of elevating efficacy for aplastic anemia (AA) by using blood-activating and stasis-eliminating drugs. METHODS: Immune-induced aplastic anemia model was established. Each mouse was gastrogavaged by 0.2 ml 100% composite blood-activating decoction (CBAD) twice a day. On the 10th day, the bone marrow histology, CFU-F, adhesive function of the cultured stromal cell layer, bone marrow PO2 were observed. RESULTS: In CBAD group, the WBC count, bone marrow karyocytes, bone marrow hematopoietic tissue volume, CFU-F count were significantly higher than those in AA group (P < 0.01). Moreover, the adhesive function of stromal cells and bone marrow PO2 recovered to normal level. CONCLUSION: The commonly used composite blood-activating decoction could promote the recovery and oxygen-supply of bone marrow microenvironment in AA mice, and improved the bone marrow hematopoiesis.

Anemia, Aplastic↗
PubMed1998

[A novel gene delivery system targeting to epidermal growth factor receptor overexpressing cancer cells].

A polypeptide with 33 amino acid residues was designed and synthesized. Its C terminal was composed of multiple lysine residues, which played as a DNA condensing agent, whereas the N terminal was the receptor binding domain of Epidermal Growth Factor(N32-K48). Through a spontaneous self-assembly process with electrostatic interaction, the synthetic peptide combined with a luciferase expression vector, pEBluc, to form an EGF receptor targeting nucleic acid complex. Significant luciferase activity was detected 48 hours after adding this complex directly to the culture medium of the A431 cells. This synthetic peptide could be used to construct a gene transfer system mediated by the endocytosis via EGF receptor. It promoted a very possibility of the gene therapy for the cancers such as glioma, melanoma and squamous carcinoma which are known of epidermal growth factor receptor overexpression.

Carcinoma↗
PubMed1998

[Determination of germanium and selenium in malt powder by GFAAS].

A method for determination of germanium and selenium in malt powder has been developed by graphite furnace atomic absorption spectrometry with L'vov platform. While (Pd+Ni) and Pd were used as matrix modifiers,the ashing temperatures of Ge and Se were increased to 1400 and 1200 degrees C respectively,and the matrix inferences were removed. The characteristic masses are 31 pg Ge and 23pg Se(0.0044 A), the detection limits are 28pg Ge and 62pg Se (3 sigma), the precisions (n = 9) are 3. 7-5.6%(Ge) and 4.3-6.5% (Se) and the recoveries are among 90-105%.

Edible Grain↗
PubMed1997

Meta-analysis of phenotype and genotype of NAT2 deficiency in Chinese populations.

Data on both the incidence of slow acetylator phenotype of probe drugs isoniazid, sulfadimidine or sulfamethazine, caffeine and dapsone in mainland or overseas Chinese, and the distribution of NAT2 genotypes and the frequency of NAT2 alleles in the Chinese populations were summarized and reanalysed using a meta-analysis method. Frequency of the slow acetylator phenotype in 3516 healthy Han Chinese gave an overall mean of approximately 19.9 +/- 4.0%, with the range of the combined data being between 15.8% and 25.5%. In addition, frequencies of the slow acetylator phenotype differ between the different minorities in Chinese populations and the range was between 3.2% and 50.6%, with a mean value of 20.6 +/- 12.9% in a total of 1842 individuals from 17 Chinese minorities. In addition, there was no significant heterogeneity in overseas Chinese between the probe drugs isoniazid and sulfadimidine or sulfamethazine (chi 2 = 5.97, df = 4; p > 0.05), and the mean value of slow acetylator phenotype incidence was 24.5% (119/485; 95% CI: 20.7-28.3%), consistent with that of the native Chinese. As expected, frequency of the slow acetylator genotypes in Chinese populations was 25.4% (112/441; 95% CI: 21.3-29.5%), which was in accordance with that of the slow acetylator phenotype in native or overseas Chinese. For all genotypes, *4/*4 (29.9%, 132/441), *4/*6A (27.4%, 121/441), *4/*7A (12%, 53/441) and *6A/*6A (11.3%, 50/441) occupied 80.6%, but *5A/*7A (0.2%, 1/441), *5A/*5A (1.1%, 5/441) and *7A/*7A (1.8%, 8/441) were not frequently found. From this report, the genotype frequencies of homozygous rapid acetylator, heterozygous rapid acetylator, and homozygous slow acetylator were found to be 0.299 (132/441), 0.447 (197/441) and 0.254 (112/441), respectively. Furthermore, both *4 (52.3%; 95% CI: 49-56%) and *6A (30.5%; 95% CI: 28-34%) were major NAT2 alleles, while *7A (11.2%; 95% CI: 9-13%) and *5A (6%; 95% CI: 4-8%) were uncommonly present. Frequency of the mutant alleles was observed at 0.477 (421/882 alleles). The *7A constituted 23.5% t(99/421) of slow acetylator alleles in Chinese populations, showing that this point mutation exists not only in Oriental or Asiatic, but also in Chinese populations. According to the Hardy-Weinberg equilibrium, in the phenotyped Chinese populations, the mean estimate of predicted allelic frequencies of the genotypes RR, Rr, and rr was 0.294, 0.496, and 0.210 for the Chinese, and the expected frequency of the deficient gene r was 0.458. By comparison, the predicted values are in complete agreement with the observed ones. In conclusion, this meta-analysis determined the accurate population frequencies of phenotype and genotype of the NAT2 genetic deficiency in healthy Chinese subjects.

Arylamine N-Acetyltransferase↗
PubMed1997

Molecular genetic analysis of Rts1p, a B' regulatory subunit of Saccharomyces cerevisiae protein phosphatase 2A.

The Saccharomyces cerevisiae gene RTS1 encodes a protein homologous to a variable B-type regulatory subunit of the mammalian heterotrimeric serine/threonine protein phosphatase 2A (PP2A). We present evidence showing that Rts1p assembles into similar heterotrimeric complexes in yeast. Strains in which RTS1 has been disrupted are temperature sensitive (ts) for growth, are hypersensitive to ethanol, are unable to grow with glycerol as their only carbon source, and accumulate at nonpermissive temperatures predominantly as large-budded cells with a 2N DNA content and a nondivided nucleus. This cell cycle arrest can be overcome and partial suppression of the ts phenotype of rts1-null cells occurs if the gene CLB2, encoding a Cdc28 kinase-associated B-type cyclin, is expressed on a high-copy-number plasmid. However, CLB2 overexpression has no suppressive effects on other aspects of the rts1-null phenotype. Expression of truncated forms of Rts1p can also partially suppress the ts phenotype and can fully suppress the inability of cells to grow on glycerol and the hypersensitivity of cells to ethanol. By contrast, the truncated forms do not suppress the accumulation of large-budded cells at high temperatures. Coexpression of truncated Rts1p and high levels of Clb2p fully suppresses the ts phenotype, indicating that the inhibition of growth of rts1-null cells at high temperatures is due to both stress-related and cell cycle-related defects. Genetic analyses show that the role played by Rts1p in PP2A regulation is distinctly different from that played by the other known variable B regulatory subunit, Cdc55p, a protein recently implicated in checkpoint control regulation.

Basic Helix-Loop-Helix Proteins↗
PubMed1997

[Characterization of immunoblots of hydrophobic outer membrane proteins Leptospira interrogans serovar lai strain 017].

Outer membrane proteins (OMP) of Leptospira interrogans serovar lai strain 017 were extracted by using Triton X-114 (TX-114). The OMP were solubilized and phase partitioned into both the hydrophilic, aqueous phase and hydrophobic, detergent phase. TX-114 did not solubilize the protoplasmic cylinder in intact organisms. The protoplasmic cylinders contained a lot of protein bands and most of the TX-114 solubilized proteins partitioned into the aqueous phase, whereas only 14 protein bands entered the detergent phase with SDS-PAGE. Detergent phase proteins were of 5 major protein bands such as 66 kd, 39 kd, 35 kd, 27 kd, and 16 kd. Immunoblotting of the material extracted with TX-114 showed that detergent phase proteins of alone 39 kd was apparently immunoblotting with antiserum against such as whole cell of 017 strain the outer envelope of 017 strain and the immunoprotective anti-017 Mb E4B7G5. The results showed that we could separate and purify the 39 kd protein to analyse the amino acid sequence for the cloning, expression and development of genetic engineering vaccines.

Bacterial Outer Membrane Proteins↗
PubMed1997

[Change of serum lipid, apolipoprotein during cholesterol gallstone formation in rabbit model].

In order to study the formation of cholesterol gallstone through rabbit model which was induced by high cholesterol diet (HCD), we investigated the rabbits' serum lipoprotein cholesterols and apolipoprotein (apo) at 1 week (1w), 2 weeks (2w), 3 weeks (3w) and 4 weeks (4w) in comparison with those of a control group respectively. The results were as follows: (1) of 10 rabbits subjected to experiment, 4, 6, and 7 rabbits were found to have induced-cholesterol gallstones in the 2w, 3w and 4w groups respectively. (2) The serum concentrations of total cholesterol (TC), triglyceride (TG), phospholipid (PL), low density lipoprotein cholesterol (LDL-C) and very low density lipoprotein chloesterol (VLDL) increased significantly (1w, 2w, 3w and 4w groups vs control group, P < 0.05), especially in the 3w and 4w groups; the surum concentrations of high density lipoprotein cholesterol and its subfractions (HDL-C, HDL2-C, HDL3-C) decreased slightly (vs control group, P > 0.05). (3) The serum contents of apoB100, apoC II and apoC III increased significantly (vs control group, P < 0.05), especially in the 3w and 4w groups; the serum apoA I reduced gradually in 1w, 2w and 3w groups, and decreased greatly in 4w group (vs control group, P < 0.05). The results demonstrated that owing to the intake of high cholestrol diet with the passage of time, the increased concentrations of serum VLDL-C, apoB, apoC II and apoC III possibly caused an enhanced secretion of biliary cholesterol into bile; that the decreased serum apoA I level might reduce the secretion of anti-nucleating factor into bile. All of these factors and changes may play important roles during the formation of cholesterol gallstones.

Animals↗
PubMed1997

Extractive L-lactic acid fermentation with immobilized Rhizopus oryzae in a three-phase fluidized bed.

The Rhizopus oryzae was immobilized by the calcium alginate entrapment method. A three-phase fluidized-bed bioreactor was designed to perform the immobilized-cell L-lactic acid fermentation. A solvent extraction column was coupled with the bioreactor to remove L-lactic acid from the fermentation broth. The TRPO was selected as solvent and sulfonated kerosene as diluent. The results indicated that the pH value in the broth was regulated above pH 3.5 and the fermentation rate was as high as 11 g L-lactic acid per hour per liter of beads. A mathematical model was proposed to describe the concentration of L-lactic acid in the extractive fermentation.

Fermentation↗
PubMed1996

Drug leads from the Kallawaya herbalists of Bolivia. 1. Background, rationale, protocol and anti-HIV activity.

Aqueous, organic and alcoholic extracts of over 100 samples of 60 species of Kallawaya medicinal herbs representing 30 plant families were assayed to compare their toxicity and ability to protect MT-2 T-lymphoblastoid cells from the cytopathic effect of human immunodeficiency virus (HIV). The results are reported as a therapeutic index (TI) which was > 25 for eighteen species, including seven > 50 and one > 100. The anti-HIV activity resided primarily in the aqueous rather than in the organic extracts and was concentrated in plants used in ethnomedicine to treat lung and liver diseases.

Acquired Immunodeficiency Syndrome↗
PubMed1996

[The changes in mucus components of intestine after burn and their relationship with bacterial translocation].

A dynamic observation at 0.5 hr, 1 hr, 6 hr, 12 hr and 24 hr after 25% third degree burn in 363 rats: 1) The lesions of mucous membrane of ileum. 2) Assessment of the depth of mucus layer and the contents of protein, hexose and sialic acid. 3) Estimation of the content of mucus IgA, serum IgA and the number of plasma cell producing IgA in mucous membrane. 4) Bacterial culture of mesentery lymph node. The following results were achieved: 1) Serious lesions were discovered in ileal mucous membrane. 2) Mucus IgA content was reduced markedly and the reduction was related to bacterial translocation.

Animals↗